High strength leather material

ABSTRACT

A leather substrate formed from waste leather and its method of production, particularly a leather substrate made up substantially of a collagen fibril matrix.

CLAIM OF PRIORITY

The present application claims priority to and the benefit of U.S.application 62/275,512, “High Strength Leather Material” (filed Jan. 6,2016), the entirety of which application is incorporated herein byreference for any and all purposes.

FIELD OF THE DISCLOSURE

This disclosure relates to leather products formed from waste leathermaterials and their method of manufacture. Particularly, the disclosurerelates to the process of manufacture of a leather substrate material,wherein intermediate precursor leather materials allow for improvedprocessing and the end-produced leather substrate material has improvedstrength and tear resistance. Particularly, the disclosure relates toinitial shredding or grinding of collected leather waste to createleather particles of a specific size.

BACKGROUND OF THE DISCLOSURE

Conventional leather is formed by tanning animal hides. The tanningprocess treats an animal hide with a variety of substances to improveand maintain leather's desirable physical characteristics for use inclothing, upholstery, luggage and like applications. The most desirablephysical characteristics of tanned leather include appearance, feel,resilience to stretching, longevity, treatability with a variety ofsurface conditioning finishes and natural drape.

Leather's desirable characteristics are attributed in part to its beinga fibrous, semi-porous material made up of an entangled, open matrix ofresistant collagen fibers. Collagen fibers make up majority of leather'scomposition. Collagen fibers are made up of constituent collagen fibrilbundles made up in turn by smaller elongated strands of collagen proteinknown as collagen fibrils.

The tanning process is directed primarily toward collagen fibers to fixchemically reactive sites on/between adjacent collagen molecules. Thislinks the matrix of resistant collagen fiber bundles, leaving tannedleather pliable, and occupies reactive sites that otherwise would allowleather to degrade and rot. The tanning process likewise removes othercompounds from the hide that may be susceptible to degradation and/orperform other functions in the hide that may be replaced with othermaterials.

Obtaining natural leather is problematic due to supply hide havingvarying qualities, tanning process costs, varying hide costs over timeamong other challenges.

The leather harvesting, tanning and preparation process produces wasteleather byproducts in leather scraps and shavings. If not otherwiseused, the waste leather is disposed of by-landfill or incinerationcreating a negative environmental impact.

Artificial leather products containing waste leather, such as bondedleather, attempt to emulate natural leather. Bonded leather is syntheticleather formed by embedding shredded leather particles into variousbinding materials. The shredded leather and binding material substancemay be applied onto a fabric backing carrier.

Bonded leather type synthetic leathers lack the above-noted desirablecharacteristics of natural leather. This is due to synthetic leatherslacking the continuous matrix of resistant collagen fiber bundles foundin natural leather.

The failure of known artificial and synthetic leathers that containshredded leather particles is that the individual particles do notphysically interact to reproduce or emulate the characteristics of acontinuous piece of natural leather having an entangled matrix ofresistant collagen fibers. Most notably, artificial and syntheticleathers suffer as lacking desirable tensile strength qualities, otherstrength qualities and esthetic attributes.

In tests applied by a conventional tensometer, artificial and syntheticleather samples of 0.010 to 0.080 inch thickness were subjected topulling stresses under tension to failure. Measurement of maximumapplied force before failure was recorded and calculated as maximumtensile strength pound per square inch (PSI) measurements ranginggenerally from about 790 PSI to about 1750 PSI.

Likewise, given the inherently variable makeup of organic animal hidesand tanning treatments, the tensile strength qualities of tanned naturalleather can vary widely. The tensile strength of representative naturaltanned leathers were found to vary from about 2000 PSI to 3200 PSIdepending on leather quality, mechanical treatments and coatings appliedto the leather.

Processes for forming other types of formed leather substratescontaining shredded and fibrillated collagen leather fibers derived fromwaste derived leather are known. A challenge with these processes is theinability to achieve high levels of fibril dispersion so thatsubsequently formed leather substrates have the potential for fibril tofibril entanglement. Other challenges are that formed interim wet lapproducts are difficult to dewater and represent a limit to the degree offibril dispersion which can be achieved in a final leather substrateproduct. Wet lap may refer to a sheet comprising the dispersion, whereparticles or fibers are suspended in a fluid (such as a slurry) and thewet lap may be pressed or otherwise manipulated to eliminate at least aportion of the fluid.

The interim wet lap products of these processes also tend to have lowwet lap strengths. This presents possessing challenges with manipulatinginterim wet lap products in large scale production processes using knownpaper-type processing machines. During transition of the interim wet lapfrom wire mesh sections of paper-type processing machines, the wet laptends to break reducing process efficiency and making it very difficultor impossible to produce the end product on a large scale.

Thus, there is a need for an improved formed leather product that iscreated from available waste leather by-products that reproducesdesirable physical characteristics of natural leather. The improvedleather product should reproduce the collagen fiber matrix that is foundin natural leather, have predicable physical characteristics includinghigh tensile strength, desired elastic properties for a range of endapplications and treatability by conventional leather conditioningsubstances. The process of creating the improved leather product shouldallow improved de-watering of interim wet lap products and have good wetlap strength to facilitate physically manipulating interim wet lapproducts.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of prior art conventional tannedleather.

FIG. 2 is a cross-sectional view of a segment of a single collagen fiberbundle.

FIG. 3 is a view of a collection of fiber bundle segments found within aleather particle.

FIG. 4 illustrates a fiber bundle segment.

FIG. 5 illustrates a swollen fiber bundle segment.

FIG. 6 illustrates a formed collagen fibril matrix.

FIG. 7 is a flow chart illustrating example steps in a method of forminga leather substrate according to aspects of the disclosure.

FIG. 8 illustrates an example apparatus for producing a leathersubstrate material according to an aspect of the disclosure.

SUMMARY

Leather substrates may be formed by processes described generally in thepresent disclosure. Leather waste may be a source material for thematerials used to form the leather substrates described herein. Asdescribed herein, leather waste is physically processed by shredding orgrinding to create leather particles of desired size. The desired sizemay refer to particle size that provides an apparently even dispersionof leather particles in the leather particle/water mixture. That is thedesired size may provide a non-agglomerated pieces or leather particles.For example, the leather waste may be processed in a cutting, grinding,or shredding machine that allows a continuous thorough shearing orcutting of the leather to provide generally uniform sized particles. Ina specific aspect, the leather is cut or ground in machinery andscreened through apertures of approximately 3/32 of an inch in diameterto provide generally uniform leather particle pieces. However, theleather particles may not necessarily be the same size or same size andshape.

In particular, the shredding or grinding may be accomplished through useof cutting machinery capable of cutting fibrous materials into finelycontrolled particle sizes. Potential cutters may be screen classifyingcutters have multiple, staggered cutter blades that allow continuous,thorough shearing of leather waste. Cut particles are passed through ascreen having screen apertures of approximately 3/32 of an inch indiameter to assure that collected particles are acceptable and likewisehave specific and generally uniform size of about 3/32 of an inch indiameter.

Potential cutting machinery may be a Munson brand “SCC” ScreenClassifying Cutter Model No. SCC-15-SS, or like cutter.

Potential method aspects may include use of a Munson screen classifyingcutter or like screen classifying cutter machinery that has a number ofrotating cutting blades and stationary bed knives, wherein the distancebetween the rotating cutting blades and stationary bed knives can beadjusted. In such aspects, in addition use of a screen having screenapertures of approximately 3/32 of an inch in diameter, the distancebetween the rotating cutting blades and stationary bed knives should beset to about 0.05 inches.

Potential cutting machinery may also be a rotary-knife mill capable ofshredding the leather waste until the particles are small enough to dropthrough a screen having screen apertures of approximately 3/32 of aninch in diameter.

Use of such a screen classifying cutter provides reliable formation ofwaste leather particles as a raw material for forming a leathersubstrate by the processes described generally in the presentdisclosure.

Formed waste leather particles may not necessarily all be of the samesize. In particular, a percentage of particles maybe generally sphericalhaving a diameter of approximately 3/32 of an inch or less in size.Particles may also be elongate, having a cylindrical strand orthread-like structure with a major axis extending at lengths greaterthan 3/32 of an inch and with a cross sectional diameter ofapproximately 3/32 of an inch or less in size.

The leather particles are combined with a fluid, such as water, to forma particle/water mixture, also referred to as a leather/water particlemixture. The mixture is subjected to physical mixing or agitation bymechanical dispersion devices. Potential dispersion devices may berefiners such as double disk refiners or conical refiners as known inthe paper manufacturing processes. Other potential dispersion devicesmay be beaters as conventionally known in paper processing machinery,such as Hollander-type beaters.

A polymer latex may be added to the water/leather particle mixture.Exemplary polymer latex may include an acrylic latex polymer such asacrylonitrile latex polymer. Polymer latex may further include, but isnot limited to acrylonitrile-butadiene styrene (ABS), styrene-butadienestyrene, acrylonitrile-ethylene-butadiene-styrene, methylmethacrylate-butadiene styrene, polybutadiene, or styrene acrylonitrilelatex polymers, among others. In some aspects, the polymer latexcomprises about 50% polymer. In some aspects, certain salts may be addedto the water/leather particle mixture either before or after theaddition of the polymer latex. Added salts may include salts ofmagnesium, strontium and calcium. In particular, added salts mayinclude: magnesium chloride MgCl₂ and hydrated forms thereof, calciumchloride CaCl₂, magnesium sulfate Mg₂SO₄ and hydrated forms thereof,strontium chloride SrCl₂, and hydrated forms thereof. Other salts mayalso be effective, not limited to the above listed divalent cationicsalts, including: barium chloride BaCl₂, iron(II) chloride FeCl₂,magnesium bromide MgBr₂, and magnesium iodide MgI₂, for example. Ionicsalts may be included so as to provide a water/leather particle mixturecomprising up to about 25 wt. % of one or more ionic salts. In oneaspect, the water/leather particle mixture comprises about 2% CaCl2 and2.5% MgCl₂.6H₂O (magnesium chloride hexahydrate).

In additional formation steps, the water/leather particle mixture isformed or extracted into a sheet or other structure, often described asa wet lap, for example, that can be physically manipulated, anddewatered. In aspects, the mixture is extracted into a sheet using wetlaid composite processes similar in part to paper making processes asdescribed in the present disclosure.

Precursor sheets of wet laid leather material formed from leatherparticles shredded or ground by this method allow formation of sheetsthat are generally uniform and free of clumps of particles that formundesired “lumps” or “ropes” within the sheets. These non-uniform“lumps” or “ropes” weaken the structural integrity of the sheets,resulting in formation of a lower-strength end-product. Formedend-products have improved strength and tear resistance over prior-knownleather products formed from waste leather.

Disclosed is a formed leather product created from commonly-availablewaste leather byproducts and its method of manufacture. The formedleather product reliably reproduces desirable physical characteristicsof natural leather including high tensile strength and desired elasticproperties for end applications and treatability by conventional leatherconditioning substances.

The improved leather product includes a formed leather substratecontaining a matrix formed by collagen fibrils. The collagen fibrilmatrix is formed from entangled collagen fibrils derived from collagenfibril bundles and collagen fibers found in naturally occurring leather.

The formed leather substrate is formed by obtaining leather waste andphysically processing the waste by shredding or grinding to createleather particles of desired size as described herein. The leatherparticles are combined with water to form a particle/water mixture. Themixture is processed to allow collagen fibril bundles within theparticles to absorb a quantity of water. The water absorption swells andpartially distresses the collagen fibril bundles. Distressing of thecollagen fibril bundles may refer to the fibril bundles of the leatherparticles separating or partially separating from one another. Forexample, ends of individual collagen fibrils may begin to separate fromamong the collagen fibril bundles. The partially distressed bundles areparticularly susceptible to mechanical dispersion. Mechanical dispersionof the swollen, partially distressed fibril bundles extracts a highyield of constituent collagen fibrils from the bundles to theparticle/water mixture. Water is then removed from the mixture through aseries of dewatering steps to form a leather substrate productcontaining a matrix of collagen fibrils, bundles and fibers.

The process allows improved de-watering of interim wet lap products.Formed interim wet lap products have improved wet lap strength tofacilitate physically manipulating the interim wet lap products. Leatherproducts containing the collagen fibril matrix substrate have improvedtensile strength qualities over known artificial and synthetic leathers.In tests by conventional tensometer, samples of leather substrateproducts are subjected to pulling stresses under tension to failure todetermine maximum applied force measurements before failure.Measurements recorded and calculated as maximum tensile strength werewell above known artificial and synthetic leathers and many naturaltanned leather samples.

Leather products containing the collagen fibril matrix substrate sharethe desirable physical characteristics of conventional leather and maybe treated by leather mechanical enhancement techniques such asembossing, calendaring, staking, tumbling and so forth. The formedleather substrate and its method of manufacture are disclosed herein.

Other objects and features of the leather substrate will become apparentas the description proceeds, especially when taken in conjunction withthe accompanying drawing sheets illustrating aspects of the leathersubstrate.

A process of forming a leather substrate may comprise collecting aportion of leather waste material; shredding and screening the leatherwaste material to provide leather material particles comprising collagenfiber bundles; combining the leather material particles with a portionof a fluid or water to provide a water/leather material particle or afluid/leather material particle solution; allowing collagen fiberbundles of the leather material particles to absorb at least a portionof the fluid or water; shearing the leather material particles;dispersing the leather material particles; forming a wet lap or pulpcomprising the leather material particles; removing at least a portionof the fluid or water from the fluid/leather material particle solutionor from the water/leather material particle solution.

In some aspects, a process of forming a leather substrate may comprisemanipulating a leather material to form leather material particles;combining the leather material particles with a fluid to form a leathermaterial solution; agitating the leather material solution; and removingat least a portion of the fluid from the leather material solution toform a leather substrate.

A leather substrate formed according to the method disclosed hereinwherein the leather substrate exhibits a tear resistance of greater thanabout 20 Newtons when tested in accordance with ASTM D 4704.

DETAILED DESCRIPTION

FIG. 1 is a magnified cross-sectional view of conventional tannedleather 10. Leather 10 is made up by numerous elongate, entangledcollagen fibers 12 that cooperate to form an open tanned leather matrix14.

FIG. 2 is a cross-sectional representational view of a single collagenfibril bundle 16 segment made up of constituent elongated bundles ofcollagen fibrils 18. It is understood that FIG. 2 is a representationalview and that in naturally-occurring collagen fibril bundles, theconstituent elongated bundles of collagen fibrils would not be alignedin uniform, parallel formation.

The disclosed leather substrate is formed from processing collectedscrap leather byproducts derived from conventional leather processingsteps.

Collected scrap leather byproducts are ground or shredded into particles20 of desired size containing leather material including fibril bundles16. Collagen fibril bundles 16 are subjected to water absorption anddistressed though swelling steps described below to form swollen fibrilbundles 22. Swollen fibril bundles 22 contain quantities of absorbedwater 23 that partially fibrillates the bonds between adjacent collagenfibrils 18. Distressed swollen fiber bundle segments 22 containfibrillated constituent collagen fibrils 18′ as shown in FIG. 5.

The water absorption likewise distresses and partially fibrillates thebonds between adjacent collagen fibers 12 in a particle 20.

Swollen fiber bundle segments 22 are subjected to mechanical dispersionsteps to extract elongate constituent collagen fibrils 18. Collagenfibrils 18 are collected and processed to form collagen fibril matrix 24as detailed below.

The collagen fibril matrix 24 is made up of a number of individualcollagen fibrils 18 derived from collagen fiber bundles 12. Eachcollagen fibril 18 has an elongate body having a cross-sectionaldiameter generally less than 10 micrometers, and a length generally manytimes its diameter, each collagen fibril physically engaged andentangled with adjacent collagen fibrils to form collagen fibril matrix24. Collagen fibril matrix 24 contains a plurality of fine gaps 26between adjacent collagen fibrils 18 to form an overall open and porousmatrix structure.

Methods of forming leather substrates containing collagen fibril matrix24 are described below.

The flowchart of FIG. 7 discloses a method 28 of producing a leathersubstrate containing the collagen fibril matrix from leather byproduct.

Starting at step 30, leather byproduct waste is collected. Potentialbyproduct leather waste could be scrap leather waste byproducts producedin tanning processing steps or leather waste from articles manufacturefrom tanned leather.

At step 32, byproduct leather waste is shredded or ground and screenedto form de-agglomerated byproduct particles 18 of a desired size.Particles are passed through a screen having screen apertures of aselected size to assure collected particles 18 are of a like selectedsize. At step 34, collected particles 18 are mixed with a quantity ofwater to form a particle/water mixture.

Particles 20 become swelled with water from the particle/water mixture.Particle swelling is a result of particle collagen fibril bundlesabsorbing water from the particle/water mixture to form swollen fibrilbundle segments 22 at step 36. The swollen fibril bundle segments arepartially distressed, causing partial separation of constituent fibrilswhich allows improved bundle dispersion in later processing steps.

At step 38, the particle/water mixture is sheared and dispersed by adispersion device. The dispersion device subjects particles 20 withinthe particle/water mixture to shear forces that separate collagenfibrils 18 from particle collagen fibril bundles 16. The dispersionprocess shreds particles 20 and further distresses particle collagenfibril bundles to separate collagen fibrils 18 from particle collagenfibril bundles 12.

Potential dispersion devices may be refiners such as a double diskrefiner or conical refiner as are known in the paper manufacturingprocesses. Other potential dispersion devices may be beaters asconventionally known in paper processing machinery, such asHollander-type beaters.

Step 38 dispersion of the particle/water mixture is conducted for aperiod of time required to obtain desired fibril dispersion. A desiredfibril dispersion may refer to a non-agglomerated pieces or leatherparticles throughout the dispersion. To an observer, the fibrildispersion may appear substantially uniform. With too much mixing,individual leather fibers may begin to agglomerate. The desired fibrildispersion may have no or substantially no agglomerates of leatherfiber, that is, there may be a generally even dispersion or distributionof leather fibrils.

At step 40, water is removed from the particle/water mixture to form asubstrate wet lap. Water is removed from the particle/water mixture toform a wet lap so that the wet lap is sufficiently strong formanipulation. In some aspects, the wet lap may include from about 40weight percent (wt. %) to about 60 wt. % water. In further aspects, thewet lap may include up to 80 wt. % water.

Water is further removed from the substrate wet lap to form a leathersubstrate by steps known in conventional paper manufacturing usingmachinery as known to convert wet paper pulp to a dried paper product.For instance, draining of the particle/water mixture to form a substratewet lap may be effected through use of a Fordriner-type machine havingvarious pressing and drying operations as explained in greater detailbelow.

At step 42, water is removed from the substrate wet lap to form aleather substrate containing primarily by-weight of solids and aremainder by-weight of water. As water is removed from the substrate wetlap, separated collagen fibrils 18 within the particle/water mixturephysically interact with each other. As adjacent fibrils becomephysically engaged with each other, leather substrate collagen fibrilmatrix 24 is formed at step 44. Step 52 water removal may be effectedthrough use of a Fordriner-type machine as explained in greater detailbelow.

FIG. 8 illustrates an apparatus 100 for producing a leather substrate inaccordance with the steps shown in the FIG. 7 flowchart. Apparatus 100may include elements commonly found in Fordriner-type paper processingmachines.

In apparatus 100, waste leather 102 is selected and physically processedby shredding or grinding in shredder or grinder 104. Waste leather 102is selected as described in step 30 of the FIG. 8 flowchart.

Initially collected waste leather 102 may come in the form of scrapsfrom other leather tanning and treatment processes. Shredder or grinder104 initially de-agglomerates shavings that may have become clumped dueto water content or are compacted during bailing or other packagingmethods and also grinds larger particles to a desired size.

Physical processing by shredding or grinding forms initially shreddedleather particles 106. Initially shredded leather particles 106 arescreened through screening machine 108 to select leather particles 20 ofa desired size and to screen out unwanted waste that may have passedthrough shredder 104 as described in step 32 above.

Alternatively, a grinder may be used having an integrated screen toselect processed leather particles having desired size criteria. Leatherparticles 20 are next mixed with water 23 in a mixing chest or mixingtank 110 to form a water/leather particle mixture 112 containing apercentage of leather particles by-weight as described in step 34 above.

Leather particle collagen fibril bundles absorb water 23 from theparticle/water mixture to form swollen fibril bundles 22 at step 38.Water/leather particle mixture 112 is delivered to a dispersion tank116. Dispersion tank 116 includes a dispersion refiner 118, such as adouble disk refiner, a conical refiner or Hollander-type beater as isknown in the paper manufacturing art.

Dispersion refiner 118 subjects leather particles 20 within mixture 112to shear dispersion forces as described in step 40 above. Alternatively,water/leather particle mixture 112 may be separately delivered to adispersion device and returned to mixing tank 110 for processing beforedrying steps are undertaken.

Water is separated from mixture 112 to form a wet lap slurry 122. Wetlap slurry 122 is transferred from dispersion tank 116 to processingmachine 124 for dewatering as described in step 50 above.

Processing machine 124 may be a Fourdrinier-type machine typically usedin the making of paper having a head box 125 and a transfer assembly 126including wire mesh section 128, one or more wet presses 130, dryer cans132 and calendaring rollers 134. Initially, wet lap slurry 122 istransferred to proceeding machine head box 125 and to wire mesh section128 wire mesh endless belt 136. Wire mesh endless belt 136 is made up ofa wire meshing to allow initial draining of wet lap slurry 122 and isdriven by rollers 138. Vacuums 140 may be used to assist in dewateringwet lap slurry 122.

Dewatering by wire mesh section 128 sufficiently dewaters wet lap slurry122 to form wet lap 142. Wet lap 142 is transferred further alongtransfer assembly 126 from wire mesh section 128 to one or more wetpresses 130 for additional mechanical dewatering by presses 144.

Wet lap 142 is further transferred along assembly 126 from wet presses130 to drier section 132 for final dewatering by drying. Drier section132 may include a heated felt dryer known in the paper making art.

At this point in the process, wet lap 142 has been sufficientlydewatered to form a leather substrate 148 having desired moisturecontent and containing a collagen fibril matrix 24 as described in steps52 and 54 above.

The present disclosure relates at least to the following aspects.

Aspect 1. A method of forming a leather substrate material comprising:

collecting a portion of leather waste material; shredding and screeningthe leather waste material to provide leather material particlescomprising collagen fiber bundles; combining the leather materialparticles with a portion of a fluid or water to provide a water/leathermaterial particle or a fluid/leather material particle solution;allowing collagen fiber bundles of the leather material particles toabsorb at least a portion of the fluid or water; shearing the leathermaterial particles; dispersing the leather material particles; forming awet lap or pulp comprising the leather material particles; removing atleast a portion of the fluid or water from the fluid/leather materialparticle solution or from the water/leather material particle solution.

Aspect 2. A method of forming a leather substrate material comprising:manipulating a leather material to form leather material particles;combining the leather material particles with a fluid to form a leathermaterial solution; agitating the leather material solution; removing atleast a portion of the fluid from the leather material solution to forma leather substrate wherein the leather substrate exhibits a tearresistance of greater than about 20 Newtons when tested in accordancewith ASTM D 4704.

Aspect 3. The method of aspect 2, wherein the leather material compriseswaste leather collected from tanning waste.

Aspect 4. The method of aspect 2, wherein agitating the leather materialsolution comprises physically mixing the leather material solution.

Aspect 5. The method of aspect 2, wherein processing the leathermaterial comprises grinding or reducing the leather material to aparticulate form.

Aspect 6. The method of aspect 2, further comprising adjusting pH of theleather material solution.

Aspect 7. The method of aspect 2, wherein the ionic salts includemagnesium chloride, calcium chloride, magnesium sulfate, strontiumchloride, barium chloride, iron(II) chloride, magnesium bromide, andmagnesium bromide, or a combination thereof.

Aspect 8. The method of aspect 2, wherein the adding the ionic salt tothe leather material solution effects an ionic salt content of up toabout 25%.

Aspect 9. The method of aspect 2, wherein the polymer latex comprises anacrylic polymer latex.

Aspect 10. The method of aspect 2, wherein the adding a polymer latex tothe leather material solution effects a polymer content of about 25%combined leather material particles and latex polymer solids.

Aspect 11. A leather substrate material formed by a process comprising:manipulating a leather material to form leather material particles;combining the leather material particles with a fluid to form a leathermaterial solution; adding a polymer latex to the leather materialsolution; adding an ionic salt to the leather material solution;removing at least a portion of the fluid from the leather materialsolution to form a leather substrate.

Aspect 12. The leather substrate of aspect 11, wherein the leathersubstrate exhibits a tear resistance of greater than about 20 Newtonswhen tested in accordance with ASTM D 4704.

Aspect 13. The leather substrate of aspect 11, wherein manipulating theleather material comprises grinding or reducing the leather material toa particulate form.

Aspect 14. The leather substrate of aspect 11, wherein manipulating theleather material comprises shredding the leather material.

Aspect 15. The leather substrate of aspect 11, further comprisingadjusting pH of the leather material solution.

Aspect 16. The leather substrate of aspect 11, further comprising addinga polymer latex.

Aspect 17. The leather substrate of aspect 11, further comprising addingan ionic salt.

Aspect 18. The leather substrate of aspect 16, wherein the polymer latexcomprises an acrylic polymer latex.

Aspect 19. The leather substrate of aspect 16, wherein the adding apolymer latex to the leather material solution effects a polymer contentof about 25% combined leather material particles and latex polymersolids.

Aspect 20. The leather substrate of aspect 11, wherein the leathersubstrate exhibits a tear resistance of greater than about 20 Newtonswhen tested in accordance with ASTM D 4704.

It is also to be understood that the terminology used herein is for thepurpose of describing particular aspects only and is not intended to belimiting. As used in the specification and in the claims, the term“comprising” may include the aspects or aspects “consisting of” and“consisting essentially of.” Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. In this specification and in the claims which follow, referencewill be made to a number of terms which shall be defined herein.

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a glass fiber”includes mixtures of two or more such glass fibers.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint. It is also understood that there are a number of valuesdisclosed herein, and that each value is also herein disclosed as“about” that particular value in addition to the value itself. Forexample, if the value “10” is disclosed, then “about 10” is alsodisclosed. It is also understood that each unit falling within a rangebetween two particular units are also disclosed. For example, if 10 and15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event, condition, component, or circumstance mayor may not occur, and that the description includes instances where saidevent or circumstance occurs and instances where it does not.

As used herein, the term or phrase “effective,” “effective amount,” or“conditions effective to” refers to such amount or condition that iscapable of performing the function or property for which an effectiveamount is expressed. As will be pointed out below, the exact amount orparticular condition required may vary from one aspect or aspect toanother, depending on recognized variables such as the materialsemployed and the processing conditions observed. Thus, it is not alwayspossible to specify an exact “effective amount” or “condition effectiveto” for each aspect or aspect encompassed by the present disclosure.However, it should be understood that an appropriate effective amount orcondition effective to achieve a desired results will be readilydetermined by one of ordinary skill in the art using only routineexperimentation.

As used herein, “fibrils” refers to fine fiber-like materials. Leathermaterials described herein may comprise fibrils which may associatetogether in bundles to form larger bundles, often described as leatherbundles or leather fibers. The leather bundles or leather fibers orleather fiber bundles may be comprised of a subassembly of fibrils.

As used herein, “polymer latex” may refer to an aqueous colloidaldistribution of polymer particles.

Disclosed are the components to be used to prepare disclosedcompositions of the invention as well as the compositions themselves tobe used within methods disclosed herein. These and other materials aredisclosed herein, and it is understood that when combinations, subsets,interactions, groups, etc. of these materials are disclosed that whilespecific reference of each various individual and collectivecombinations and permutation cannot be explicitly disclosed, each isspecifically contemplated and described herein. This concept applies toall aspects of this application including, but not limited to, steps inmethods of making and using the compositions of the invention. Thus, ifthere are a variety of additional steps that can be performed it isunderstood that each of these additional steps can be performed with anyspecific aspect or combination of aspects of the methods of theinvention.

References in the specification and concluding claims to parts byweight, of a particular component in a composition or article, denotesthe weight relationship between the element or component and any otherelements or components in the composition or article for which a part byweight is expressed. Thus, in a composition containing 2 parts by weightof component X and 5 parts by weight component Y, X and Y are present ata weight ratio of 2:5, and are present in such ratio regardless ofwhether additional components are contained in the compound.

A weight percent of a component, unless specifically stated to thecontrary, is based on the total weight of the formulation or compositionin which the component is included. For example if a particular elementor component in a composition or article is said to have 8% weight, itis understood that this percentage is relation to a total compositionalpercentage of 100%.

Each of the component starting materials disclosed herein are eithercommercially available and/or the methods for the production thereof areknown to those of skill in the art.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Otheraspects of the invention will be apparent to those skilled in the artfrom consideration of the specification and practice of the inventiondisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope and spirit of theinvention being indicated by the following claims.

What is claimed:
 1. A method of forming a leather substrate materialcomprising: cutting a leather material to form leather materialparticles comprising collagen fiber bundles; screening the-leathermaterial particles to obtain screened leather material particles thatare smaller than a size of screening apertures used; combining thescreened leather material particles with a fluid to form a solution,wherein the collagen fiber bundles of the screened the leather materialparticles absorb at least a portion of the fluid; adding a polymer latexto the solution; causing the collagen fiber bundles to be dispersed inthe solution; and removing at least a portion of the fluid from thesolution.
 2. The method of claim 1, wherein the processing the leathermaterial comprises subjecting the leather material to a shredding orgrinding process to a particulate form.
 3. The method of claim 1,wherein the causing the screened leather material particles to bedispersed in the solution comprises agitating or physically mixing thesolution.
 4. The method of claim 1, wherein the screening the leathermaterial particles comprises passing the leather material particlesthrough a screen having apertures of about 3/32 inch diameter to provideleather material particles each having a size of less than about 3/32inch diameter.
 5. The method of claim 1, further comprising adjusting pHof the solution.
 6. The method of claim 1, further comprising adding oneor more ionic salts and wherein the ionic salts include magnesiumchloride, calcium chloride, magnesium sulfate, strontium chloride,barium chloride, iron(II) chloride, magnesium bromide, and magnesiumbromide, or a combination thereof.
 7. The method of claim 1, furthercomprising adding a one or more ionic salts and wherein the adding theone or more ionic salts to the solution results in the solution havingan ionic salt content of up to about 25%.
 8. The method of claim 1,wherein the polymer latex comprises an acrylic polymer latex.
 9. Themethod of claim 1, wherein the screened leather material particles eachare sized less than 3/32 inch.
 10. The method of claim 1, wherein theremoving at least a portion of the fluid from the solution to form aleather substrate comprises causing at least a portion of the solutionto pass through a mesh medium to provide a wetlap and comprises one ormore of pressing or drying the wetlap to provide the leather materialsubstrate.
 11. A leather substrate formed by a process comprising:manipulating a leather material to form leather material particles;screening the leather material particles to obtain screened leathermaterial particles that are smaller than a size of screening aperturesused to screen the leather material particles; combining the screenedleather material particles with a fluid to form a solution; adding apolymer latex to the solution; adding an ionic salt to the solution; andremoving at least a portion of the fluid from the solution to form aleather substrate.
 12. The leather substrate of claim 11, wherein theleather substrate exhibits a tear resistance of greater than about 20Newtons when tested in accordance with ASTM D
 4704. 13. The leathersubstrate of claim 11, wherein manipulating the leather materialcomprises shredding the leather material.
 14. The leather substrate ofclaim 11, further comprising adjusting pH of the solution.
 15. Theleather substrate of claim 11, wherein the adding the ionic salt to thesolution results in the solution having an ionic salt content betweenabout 2% and about 6%.
 16. The leather substrate of claim 11, whereinthe polymer latex comprises an acrylic polymer latex.
 17. The leathersubstrate of claim 11, wherein the screening the leather materialparticles comprises causing the leather material particles to passthrough a screen having screen apertures of about 3/32 of an inch.